Flexible diaphragm



Aug. 4, 1925.

C. A. DUNHAM FLEXIBLE DIAPHRAGM Filed April 5, 1922 Patented Aug. 4, 19 25.

UNITED STATES CLAYTON A. DUNHFM, OF GLENCOE, ILLINOIS.

FLEXIBLE DIAPHRAGM.

Application filed April 3, 1922. Serial No. 549,864.

To all whom it may concern:

Be it known that I, CLAYTON A. DUN- HAM, a citizen of the United States, residing at Glencoe, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Flexible Diaphragms, of which the following is a specification.

My invention relates to flexible diaphragms, and has for its principal object the provision of a new and improved form and arrangement of parts by which a movable plate is connected with a surounding relatively stationary casing part by an imperforate longitudinally expandible and contractile diaphragm structure whereby the casing may be utilized for holding fluid under pressure on one side of said movable plate without the necessity for using any packing between the casing and the means provided on the opposite side of the movable plate for giving the movable plate the desired movement.

It is another object of my invention to improve devices of this type in such a manner that when one end of the device is moved toward or from theother end the strain is distributed over a very wide area with very little relative movement between any two closely adjacent portions;

It is another object of my invention to im rove devices of this t pe in sundry details hereinafter pointe out. The preferred means by which I have accomplished my several objects are illustrated in the drawing and are hereinafter specifically described. That which I believe to be new and desire to cover by Letters Patent is set forth in the claims.

In the drawing Fig. 1 is a central vertical section through a structure embodying my improved construetion.

Fig. 2 is a horizontal cross section taken on line 2-2 of Fig. 1.

Fig. 3 is a vertical section taken substantially on line 3-3 of Fig. 1, but with the spindle removed.

Fig. 4 is a horizontal cross section taken on line 4-4. of Fig. 1, and

Fig. 5 is a central, vertical section through the movable plate of my improved structure, illustrating a modified form.

In devices of this type in use heretofore in connection with valves and like structures, diaphragms have been employed comprising tubular sheet metal parts having deep convolutions, plaits or corrugations pressed therein circumferentially. In the product1on of such devices, the sheet metal is, in many instances, very materially weakened at some points owing to undue forcing of the metal or to other causes resulting in an uneven distribution of the metal. Moreover, in the expansion or contraction of such a diaphragm longitudinally thereof, the bending of the metal occurs chiefly or entlrely at the innermost and the outermost points of the plaits instead of being distributed over the whole extent of the sheet metal structure. I have found that by building up my diaphragm structure from a considerable number of separate pieces for providing the circumferential grooves or 'plaits,

and by corrugating the transversely disposed portions concentrically, I can cause the straln to be spread substantially evenly throughout the whole extent of the diaphragm, whereby the strain at any one point is very small and the tendency of the metal to crystallize and break is substantially overcome.

Referring now to the several figures .of the drawing for a description of the referred means by which I have accom lis ed my object, 10 indicates a plate which is movable vertically within a housing or casing 11 of any appropriate form. The plate shown in Fig. 1 is of a type designed for use as the holder for the gasket or seating member of a valve, being provided on its under face with an integrally formed screw threaded lug 12 adapted to receive a suitable cap for holding the gasket in position. In Fig. 5 I have shown a modified form of plate 13 similar to that shown in Fig. 1, the bottom lug lbeing tapped out rather than exteriorly threaded.

The movable plate is provided on its upper face with a central stud 15 (see Figs. 1

and 5) which is provided with a groove 16- extending entirely across its upper end, being also cored or machined out partially across at 17 immediately below the groove 16, the arrangement being such that undercut lugs 18 are provided.

Mean are provided adapted to cooperate with the lugs 18 for giving the movable plate the desired movement, comprising a stem or spindle 19, having a reduced portion 20 and a head 21 formed integrally on its lower end portion. The arrangement is such that the head 21 is adapted to be moved transversely into position below the undercut lugs 18 so as to cause the movable plate to move ositively with the stem or splndle when suc stem or spindle is given a longitudinal movement. Inasmuch as the stem 19, the reduced portion 20 and the head 21 are all circular in cross-section and are concentrically .disposed with respect to each other and with respect to the movable plate, it will be understood that the spindle is free to rotate without causing corresponding rotation of the movable plate.

In the construction shown, the spindle 19 is cut away at opposite sides at its upper end portion and is provided with transversely disposed grooves 22 in the flat faces, by means of which grooves, connection may be eflected with other cooperating actuating means.

Referring now particularly to Fig. 1 with reference to my improved built-up diaphragm, 23 indicates a horizontally disposed plate of thin sheet metal provided with a downwardly extending flange 24 at its outer edge so as to embrace the upper end of the casing 11. The plate 23 is to be secured in osition in any suitable manner, preferably 1n such a way as to be readily detachable from the casing 11. A second plate 25 of thin sheet metal is secured tightly in position about the movable plate 10, being secured in position in'the construction shown by means of a downwardly extending flange 26 which is preferabl soldered about the periphery of the mova le plate. Between the plate 23 and the plate 25, I have provided a plurality of pairs of horizontally disposed plates 27 and 28 which are flanged on their outer edges for connection to each other. Each of the plates 23, 25, 27 and 28 is also flanged along its inner edge to provide for connecting the several pairs of plates 27 and 28 together in series between the end plates 23 and 25, the connection between the overlapping flanges of the several plates being efi'ected in each instance by means of soldering or in any other suitable manner.

As is clearly shown in said Fig. 1, each of the plates 23, 25, 27 and 28 is provided with a series of annular corrugations ressed therein, such corrugations being re atively quite shallow so as to insure that the sheet metal shall not be weakened to any material extentat any point. By reason of the provision of the concentric corrugations in the several horizontally disposed plates of the diaphragm, such plates are enabled to yield longitudinally of the structure much more readily, the bending taking place at the various corrugations and be1n distributed throughout the entire area of t e sheet metal structure rather than being limited to the inner and outer edge ortions of the plates. Indeed, by reason 0 the fact that the diaphragm structure is of'double thickness at the points where the flanges overlap, it is clear that the bending of the sheet metal at the inner and outer junction points is quite limited as compared with that at other points where there is only one thickness of sheet metal. By reason of my improved construction which provides for spreading the strain throughout the entire diaphragm structure comprising one or more pairs of plates 27 and 28 between the end plates 23, and 25, the bending at any one point is kept at a minimum and the life of the diaphragm is thus very materially lengthened.

, In the assembling of the complete diaphragm structure, as shown in Fig. 1, the head 21 of the spindle 19 is first moved transversely into engagement with the undercut lugs 18. The built-up diaphragm is then placed into position about the spindle 19 and the stud 15, serving to prevent withdrawal of the spindle 19 from its operative engagement with the plate 10. The lower sheet metal plate 25 is then secured in position, thus completing the operative unit which is adapted then to be removably secured within the casing 11, as above described. As will be appreciated, the stud 15 and the spindle 19, in position within the drum-like diaphragm structure, serve as a guide or brace for the flexible diaphragm to prevent lateral flexing of the structure as a whole.

While I prefer to employ the construction illustrated in the drawing and above described, it will be understood that I do not wish to be restricted to the use of the precise details shown, except as such detailed construction is hereinafter specifically claimed, since it is evident that the structure is susceptible to change without departing from the spirit of my mvention.

I claim:

1. A unit of the character described, comprising a movable plate, a spindle detachably connected with said plate, a transversely disposed end plate of thin sheet metal rigidly secured to said movable plate, a second transversely disposed end plate of thin sheet metal in spaced relation to said first named sheet metal plate, and a plurality of intermediate transversely disposed plates of thin sheet metal connected in series between said end plates forming therewith an imperforate flexible diaphragm, said diaphragm serving to prevent disconnection of said spindle from said movable plate.

2. A unit of the character described, comprising a movable plate, a spindle connected with said plate and detachable therefrom by a transverse movement with respect thereto, a transversely disposed end plate of thin sheet metal rlgidly secured to said movable .plate, a second transversely disposed end plate of thin sheet metal in spaced relation to said first named sheet metal plate, and a I plurality of intermediate transverselydlsthe upper face of said posed plates of thin sheet metal connected 1n series between said end lates forming therewith-an im'perforate flex1 le diaphragm, said diaphragmserving to hold the spindle from the transverse movement necessary for disconnection from the movable plate.

3. A unit ofthe character described, comprising a movable plate, under-cut lugs on late, a spindle having a head portion a apted to be moved transversel into operative engagement with said lugs or connecting the spindle to the movable plate, a transversely disposed end plate of thin sheet metalrigidly secured to. said movable plate, a second transversely disposed end plate of thin sheet metal in spaced relation to said first named sheet metal plate, and a plurality of intermediate transversely disposed :plates of thin sheet metal connected in series between said end plates forming therewith an imperforate flexible diaphragm.

4. A unit of t e character described, comprising a movable plate, under-cut lugs on the upper face'of said late, a spindle having a head portion a transversel into operative engagement with said lugs or connecting the spindle to the movable late, a transversely disposed end plate of t in sheet metal rigidly secured to .aid movable plate,

" transversely disposed apted to be moveda second transversely disposed end plate of thin sheet metal in spaced relation to said first named sheet metal plate, and a plurality of intermediate 7 lates of thin sheet metal connected in series between said end plates forming therewith an imperforate flexible diaphragm, said diaphragm serving to hold the spindle in substantial y centerei position with respect to the movable late for preventing withdrawal of the head rom the under-cut lugs.

5. A. unit of the character described, comprising a movable plate, a stud formed integral y on the upper face of said movable plate, and recessed from one side for providing undercut lugs, a spindle having a head portion adapted to be moved transversely into operative engagement with said lugs for connectin with said movable p ate for causing the movable plate to move positively with said spin-' dle longitudinally of the spindle, a transversely disposed end plate of thin sheet metal rigidly secured to said movable plate, a second transversely disposed end plate of thin sheet metal in. s aced relation to said first named sheet meta plate, and a plurality of intermediate transversely disposed plates of thin sheet metal connected in series between said end lates forming therewith an imperforate flexlble diaphragm.

. CLAYTON A. p

the spindle vrevolubly 

